Electronic component handler having gap set device

ABSTRACT

A gap set device for an electronic component handler is provided. The electronic component handler includes a test accessory mounted to it. The test accessory is movable between a first position away from a tool and a second position closer to the tool. A gap set device is mounted to the test accessory and the tool and has a portion movable with respect to the test accessory. When the test accessory is in the second position, the portion of the gap set device contacts the component support structure to define a gap between the test accessory and the component support structure.

TECHNICAL FIELD

This application is a continuation of U.S. patent application Ser. No.No. 11,742,262, filed Apr. 30, 2007, which claims priority to U.S.Provisional patent application No. 60/887,126, filed Jan. 29, 2007.

TECHNICAL FIELD

This disclosure relates to setting a predefined and repeatable gapbetween an electronic component support structure and an electroniccomponent test accessory.

BACKGROUND

Electronic components are handled by a wide variety of differentelectronic component handlers. These different handlers include but arenot limited to products sold by Electro Scientific Industries Inc. ofPortland, Oreg., the assignee of the present patent application. ElectroScientific Industries sells a variety of electronic component handlersincluding, but not limited to, a high volume MLCC tester sold as themodel No. 3300, a chip array tester sold as the model No. 3400, a visualtest system sold as the model No. 6650, and a chip array terminator soldas the model No. 753.

One such electronic component testing machine is described in prior artU.S. Pat. No. 5,842,579 entitled Electrical Circuit Component Handler.With reference to FIG. 2, there is shown an overall pictorial view ofthe electrical circuit component handler of U.S. Pat. No. 5,842,579, theentirety of which is incorporated herein by reference. FIG. 2illustrates a handler 10 having a plurality of test accessories thereonincluding a loading frame 12, a plurality of test modules 14 and ablowoff module 16. In operation, electronic components are passedthrough load frame 12 and are individually drawn into test seats 22found on a test plate 20. Test seats 22 typically are concentric ringsthat are continuous about test plate 20.

With more specific reference to loading frame 12 and with specificreference to FIG. 2A, load frame 12 includes a plurality of arcuatefences 13. Arcuate fences 13 allow electronic components 14 to becollected adjacent fences 13 as shown. The bases of arcuate fences 13are slightly spaced above test plate 20 as to prevent passing orcatching of electronic components beneath arcuate fences 13. The spacingbetween the arcuate fences 13 and test plate 20 defines a gap labeled bythe letter A. U.S. Pat. No. 5,842,579 indicates that the gap A is set byshims.

Test plate 20 indexes in a direction toward test modules 14 as indicatedby Arrow B as shown in FIG. 2. The electronic components are tested bytest modules 14. As test plate 20 continues to index the electroniccomponents are then withdrawn from the component handler 10 by theblowoff module 16.

With continued reference to U.S. Pat. No. 5,842,579, it may be necessaryto change test plate 20. For example, test plate 20 may require changingif it becomes worn or by way of another example, test plate 20 may bechanged to accommodate handling of different types of electroniccomponents. In such situations, the test accessories, such as load frame20, must be moved out of the way so that the old test plate may beremoved and the new test plate added. The test accessories must then beput back in place setting a proper gap between the test accessories andtest plate. As described in U.S. Pat. No. 5,842,579, this gap, and inparticular the gap between the load frame and the test plate, was set byusing shims. The exclusive use of shims is time consuming andcumbersome.

SUMMARY

An electronic component handler according to one embodiment comprises acomponent support structure received on a support surface of thehandler, a test accessory mounted to the handler for movement between afirst position remote from the component support structure and a secondposition closer to the component support structure than the firstposition and a gap set device mounted to the test accessory and having aportion movable with respect to the test accessory, wherein the portionof the gap set device is configured to contact the component supportstructure such that a gap is defined between the test accessory and thecomponent support structure when the test accessory is in the secondposition.

A method according to one embodiment taught herein comprises arranging afirst component support structure on a support surface of an electroniccomponent handler, after arranging the first component support structureon the support surface, moving a test accessory and a gap set devicetoward the first component support structure, the test accessory movablerelative to the support surface and the gap set device coupled to thetest accessory and having a portion movable with respect to the testaccessory, such that the portion of the gap set device contacts thefirst component support structure and the test accessory is spaced apartfrom the component support structure to define a gap between the testaccessory and the first component support structure, and, after definingthe gap, moving the portion of the gap set device relative to the testaccessory and away from the first component support structure.

A method according to another embodiment comprises moving a testaccessory and a gap set device away from a first component supportstructure disposed on a support surface of an electronic componenthandler, the test accessory movable relative to the support surface andthe gap set device coupled to the test accessory and having a portionmovable with respect to the test accessory, replacing the firstcomponent support structure with a second component support structure,after replacing the first component support structure with the secondcomponent support structure, moving the test accessory and the gap setdevice toward the second component support structure such that theportion of the gap set device contacts the second component supportstructure and the test accessory is spaced apart from the secondcomponent support structure to define a gap between the test accessoryand the second component support structure, and after defining the gap,moving the portion of the gap set device relative to the test accessoryand away from the second component support structure.

Other applications of the present invention will become apparent tothose skilled in the art when the following description is read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like reference numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is an exploded perspective view of a gap set device that allows arepeatable gap to be set between a load frame and a test plate;

FIG. 2 illustrates a perspective drawing of a prior art electroniccomponent handler;

FIG. 2A is a cross section of a load frame illustrating electroniccomponent and arcuate fences;

FIG. 3 illustrates a cutaway view of gap set device of FIG. 1 takenalong lines 3-3 in an operational position;

FIG. 4 illustrates a cutaway view of the gap set device of FIG. 1 in adifferent operational position;

FIG. 5 illustrates a cutaway view of the gap set device of FIG. 1 in adifferent operational position;

FIG. 6 illustrates a cutaway view of the gap set device of FIG. 1 in adifferent operational position;

FIG. 6A illustrates an alternate configuration of an air cylinder andair cylinder shaft;

FIG. 7 illustrates a hollow pneumatic airshaft for use with the firstpreferred embodiment; and

FIG. 8 illustrates an exploded reference perspective of a load framemounting to a base plate; and

FIG. 9 illustrates a kinematic adjustment to adjust the planarity of aload frame in the first preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to the figures, wherein like elements are numbered alike,there is shown a gap set device for use with an electrical circuitcomponent handler. Electronic component handlers sometimes include amoving test component, for example a test plate that holds electroniccomponents. A stationary piece, typically a test accessory, sitsadjacent the moving test component. In systems such as that described inU.S. Pat. No. 5,842,579 the gap, for example between the stationary loadframe 12 and the moving test plate 20, is set with the exclusive use ofshims. Shims are difficult to handle and create a time consuming effortto set a gap.

The preferred embodiments are described with reference to the electricalcircuit component handler illustrated in U.S. Pat. No. 5,842,579 and inparticular describe an apparatus and method used to set the gap betweena load frame 12 and a test plate 20. The present invention is notlimited for use with load frames and test plates. The present inventionapplies equally to other electronic component handling devices, forexample the devices sold by Electro Scientific Industries as model Nos.6650, 3400 and 753.

With respect to the electronic component handler of U.S. Pat. No.5,842,579, the load frame 12 is mounted on a linear bearing. The linearbearing allows the load frame to move vertically away from the testplate such that the test plate may be replaced. A retractable settingpost can extend beneath the load frame such that when the load frame islowered back into position, by sliding the load frame down the linearbearing, the gap between the load frame fences and the test plate willbe determined by the amount the setting post extends beyond the loadframe fences. After the gap has been set the load frame may be lockedinto place and the setting post retracted out of the way. As describedherein, examples of setting posts include hollow air cylinders andmicrometers.

With reference to FIG. 1 there is shown an exploded perspective view ofan electronic component handler utilizing a test plate 20. Test plate 20includes plurality of concentric test rings 22. Electronic componentsare delivered into test rings 22 through the use of a load frame 12.Load frame 12 includes a plurality of arcuate fences 13. The arcuatefences 13 are operable to deliver electronic components 11 to an areaadjacent test seats 22 as illustrated in FIG. 2A.

With continued reference to FIG. 1, load frame 12 is mounted to a linearbearing 30. Linear bearing 30 includes a base 32. As shown, base 32 isconnected to a base plate 18 of handler 10 by a kinematic mount 70. Asshown, load frame 12 is slidably received into bearing 30 via a guide34. Guide 34 may be integral with load frame 12 or may be a separatecomponent.

As shown in FIG. 1, a setting post 50 is mounted to load frame 12.Setting post 50 may be positioned in a variety of places on load frame12, including but not limited to guide 34. In the first preferredembodiment, setting post 50 includes an air cylinder 52 having anextendable shaft 58. Alternatively, the setting post 50 could be amicrometer.

As shown in more detail in FIG. 7, air cylinder 52 includes an air inlet54 and an air outlet 55. Air hoses attach to each of inlet and outlet 54and 55 to deliver air to cylinder 52 and actuate shaft 58. The distancethat shaft 58 extends from air cylinder 52 is adjustable through acollar 51. Collar 51 includes fasteners 53 that may be loosened to allowcollar 51 repositioning, thereby adjusting the distance shaft 58 extendsfrom air cylinder 52. As shown, shaft 58 includes an internal passage 59through which air flows via a pneumatic coupling 56. As described ingreater detail below, as the distal end 57 of shaft 58 approaches testplate 12 the air flow through passage 59 is obstructed. This obstructionis detected and allows a gap to be set between load frame 12 and testplate 20.

With further reference to FIG. 1, shaft 58 is extendable beneath/beyondfences 13 of load frame 12. With shaft 58 in its extended position loadframe 12 may be lowered toward test plate 20 by linear bearing 30. Whenshaft 58 comes in close proximity with test plate 20, the airflowthrough the hollow portion 59 of shaft 58 is obstructed. At this point alock 36 may be engaged to lock load frame 12 into place. As shown, lock36 includes a knob 38 for manual actuation. An automated lock may alsobe used. By extending shaft 58 a known distance past the bottom offences 13 the gap between load frame 12 and test plate 20 may beaccurately and repetitiously set. In the first preferred embodiment thegap can be set to approximately 25 microns. Generally, a gap between 1and 50 microns would be acceptable for a wide range of differentelectronic components.

With further reference to FIG. 1, it may be desirable for somepurchasers of the device of the first preferred embodiment to radiallyand axially align fences with corresponding concentric test seat rings22. As shown, such radial and axial alignment may be adjusted throughthe actuation or adjustment of micrometers 60. As further shown in FIG.1, a borescope access hole 61 may be provided to enable an operator toplace a borescope, not shown, into access hole 61 to visually inspectthe gap between load frame 12 and test plate 20 as well as the alignmentof fences 13.

With reference to FIG. 8, test plate 20 is planar. Similarly, theunderside of load frame 12, and in particular the bottom edges of fences13, define a plane. In the preferred embodiment, kinematic mount 70allows the plane defined by fences 13 to be adjusted to be parallel withthe plane defined by test plate 12. Kinematic mount 70 includes pins 72located on base plate 18 of handler 10. Pins 72 engage correspondingadjustable mounts 74 positioned on base 32. In the first preferredembodiment, kinematic mount 70 further includes a pair of pins 76 thatfit into holes 77. Pins 76 cooperate with holes 77 to prevent base 32from sliding on handler 10.

With reference to FIG. 9, the depth of each mount 74 can be changed byadjusting shaft assemblies 78. Shaft assemblies 78 include precisionadjusting knobs 79 to accomplish an adjustment of the plane defined bythe underside of fences 13. To facilitate a more precise coplanarrelationship between the plane of test plate 12 and the plane defined bythe underside of fences 13, a borescope, not shown, may be placed intoborescope access 61 for visual inspection.

With reference to FIGS. 3-6 there is shown a series of cutawayillustrations taken along line 3-3 of FIG. 1 that illustrate a firstproposed sequence of operation of the gap setting device. As shown inFIG. 6, load frame 12 is spaced away from test plate 20. This allowstest plate 20 to be removed from base plate 18 of handler 10. After areplacement test plate has been mated to base plate 18, air cylinder 52is actuated to extend shaft 58 beyond the plane defined by fences 13 ofload frame 12. An air flow is initiated through passage 59. As shown inFIG. 6, lock 36 is in an unlocked position, indicating that load frame12 will shortly be moved in a direction toward test plate 20. Load frame12 may be locked by lock 36 in its upper position.

With reference to FIG. 4, load frame 12 is moved to be adjacent to testplate 20. Because shaft 58 extends beyond the plane defined by fences13, shaft 58 will come into close proximity of load frame 12 prior tofences 13. As shaft 58 gets in close proximity with test plate 12, theair flow through passage 59 will become obstructed. This obstructed airflow may be detected such that lock 36 may be engaged as shown by arrow37 in FIG. 5. Obstruction of air flow may be indicated by a visual oraudible alarm informing a user to actuate lock 36 to set the gap betweentest plate 12 and fences 13. Alternatively, obstruction of air flowthrough passage 59 may cause an automated lock to fix the gap.

With reference to FIG. 3, it is shown that after the gap has been set bysetting post 50 and shaft 58, air cylinder 52 is actuated to retractsetting post. Retraction of setting post 50 allows test plate 20 tofreely rotate without obstruction from shaft 20.

With reference to FIG. 6A, there is shown an alternate configuration ofan air cylinder and air cylinder shaft. As shown in FIG. 6A, shaft 158includes a shoulder 159. When air cylinder 152 engages shaft 158 to itsfullest extent, shoulder 159 will engage a flange 161 machinedinternally into load frame 12. By setting the location of flange 161,the distance that shaft 158 protrudes beyond fences 13 may be fixed. Thelocation of flange 161 may be set by precisely machining load frame 12or in the alternative flange 161 may be raised or lowered by use ofshims. The shims used to raise or lower flange 161 would not have to bereplaced each time test plate 20 is replaced insofar as the shims wouldmerely fix the distance shaft 158 protruded beyond fences 13.

While the invention has been described in connection with certainembodiments, it is to be understood that the invention is not to belimited to the disclosed embodiments but, on the contrary, is intendedto cover various modifications and equivalent arrangements includedwithin the scope of the appended claims, which scope is to be accordedthe broadest interpretation so as to encompass all such modificationsand equivalent structures as is permitted under the law.

1-21. (canceled)
 22. An electronic component handler comprising: acomponent support structure received on a support surface of thehandler; a test accessory mounted to the handler for movement between afirst position remote from the component support structure and a secondposition closer to the component support structure than the firstposition; and a gap set device mounted to the test accessory and havinga portion movable with respect to the test accessory, wherein theportion of the gap set device is configured to contact the componentsupport structure such that a gap is defined between the test accessoryand the component support structure when the test accessory is in thesecond position.
 23. The electronic component handler of claim 22wherein the gap set device comprises a pneumatic cylinder having anextendable shaft, the extendable shaft mounted to contact the componentsupport structure and wherein an airflow through the extendable shaft isobstructed when the extendable shaft contacts the component supportstructure.
 24. The electronic component handler of claim 23 wherein theextendable shaft includes a shoulder extending therefrom for engagementwith a flange to limit movement of the extendable shaft relative to thepneumatic cylinder.
 25. The electronic component handler of claim 24wherein the flange is machined into the test accessory.
 26. Theelectronic component handler of claim 22, further comprising: a testaccessory support coupled to the handler and the test accessory, thetest accessory support configured to guide movement of the testaccessory between the first position and the second position.
 27. Theelectronic component handler of claim 26, further comprising: a lockengaged with the test accessory support to fix a position of the testaccessory relative to the component support structure.
 28. Theelectronic component handler of claim 22, further comprising: akinematic coupling configured to adjust an orientation of the testaccessory relative to the component support structure.
 29. Theelectronic component handler of claim 28 wherein the kinematic couplingincludes a plurality of pins on the support surface of the handler and aplurality of adjustable mounts positioned on a base of a componentsupporting the test accessory, the plurality of pins positioned forengagement with respective ones of the plurality of pins.
 30. Theelectronic component handler of claim 22 wherein the test accessory is aload frame and the component support structure is a test plate.
 31. Theelectronic component handler of claim 22 wherein the gap set devicecomprises a pneumatic cylinder with an extendable shaft mounted thereinand through the test accessory.
 32. An electronic component handler ofclaim 22, further comprising: at least one borehole through the gap setdevice to permit inspection of the gap.
 33. A method comprising:arranging a first component support structure on a support surface of anelectronic component handler; after arranging the first componentsupport structure on the support surface, moving a test accessory and agap set device toward the first component support structure, the testaccessory movable relative to the support surface and the gap set devicecoupled to the test accessory and having a portion movable with respectto the test accessory, such that the portion of the gap set devicecontacts the first component support structure and the test accessory isspaced apart from the component support structure to define a gapbetween the test accessory and the first component support structure;and after defining the gap, moving the portion of the gap set devicerelative to the test accessory and away from the first component supportstructure.
 34. The method of claim 33, further comprising: fixing aposition of the test accessory relative to the support surface afterdefining the gap and before moving the portion of the gap set deviceaway from the first component support structure.
 35. The method of claim33 wherein the first component support structure defines a first planeand the test accessory defines a second plane, the method furthercomprising: adjusting the test accessory to make the second planeparallel with the first plane.
 36. The method of claim 33 wherein movingthe test accessory toward the first component support structurecomprises linearly moving the test accessory.
 37. The method of claim33, further comprising: inspecting the gap through at least one boreholeextending through the gap set device.
 38. The method of claim 33,further comprising: moving the test accessory away from the firstcomponent support structure; after moving the test accessory away fromthe first component support structure, removing the first componentsupport structure from the support surface; after removing the firstcomponent support structure from the support surface, arranging a secondcomponent support structure on the support surface; and after arrangingthe second component support structure on the support surface, movingthe test accessory and the gap set device toward the second componentsupport structure such that the portion of the gap set device contactsthe second component support structure and the test accessory is spacedapart from the second component support structure to define a gapbetween the test accessory and the second component support structure.39. The method of claim 33, further comprising: maintaining the gapbetween the test accessory and the first component structure whilemoving the portion of the gap set device away from the first componentsupport structure.
 40. A method comprising: moving a test accessory anda gap set device away from a first component support structure disposedon a support surface of an electronic component handler, the testaccessory movable relative to the support surface and the gap set devicecoupled to the test accessory and having a portion movable with respectto the test accessory; replacing the first component support structurewith a second component support structure; after replacing the firstcomponent support structure with the second component support structure,moving the test accessory and the gap set device toward the secondcomponent support structure such that the portion of the gap set devicecontacts the second component support structure and the test accessoryis spaced apart from the second component support structure to define agap between the test accessory and the second component supportstructure; and after defining the gap, moving the portion of the gap setdevice relative to the test accessory and away from the second componentsupport structure.
 41. The method of claim 40, further comprising:maintaining the gap between the test accessory and the second componentstructure while moving the portion of the gap set device away from thesecond component support structure.